This invention relates to a hinge assembly for a compartment door that cooperates with an energy storage device. More particularly, the invention relates to an articulated hinge assembly having a movable pivot axis that cooperates with an energy storage device capable of automatically opening and holding open an unlatched compartment door.
The design of a compartment door or adjacent surrounding structure may not provide sufficient clearance for the compartment door to rotate about a stationary pivot axis when being opened. To provide sufficient clearance between a compartment door and surrounding structure, it is necessary that the pivot axis of the compartment door move as the compartment door is rotated. This problem is particularly pertinent to passenger overhead storage compartments having upwardly opening doors and located above the seats in an airplane. The upper portion of the overhead compartment door is so close to the ceiling panels of the airplane and is so constructed that insufficient clearance exists between the upper surface of the compartment door and the ceiling panel to allow the compartment door to be opened about a stationary pivot axis. The pivot axis of the compartment door must move in a direction outboard from the compartment when the compartment door is opened to allow sufficient clearance.
It is desirable to provide a hinge apparatus for an airplane overhead compartment door that will automatically rotate the door to and support the door in a first open position when the door is unlatched. For the safety of airplane passengers, it is very important that all overhead compartment doors be latched during flight. If the compartment door is unlatched and the airplane banks in making a steep turn, an item stored in the overhead compartment could force the compartment door open and could fall onto and possibly injure passengers in the airplane. Without a mechanism for auotmatically opening an unlatched compartment door, and for supporting the door in a first open position, it is difficult to determine whether a compartment door is in a latched or unlatched condition. Force is required to achieve this result and is translated to the hinge assembly, thereby placing the hinge assembly in a constantly stressed condition.
Hinge assemblies for compartment doors having a movable pivot axis are well-known in the prior art. For example, linking members pivotally connected to a compartment door and having either the pivot point or the linking member slidably mounted in a slot have been disclosed. In these devices, one or more of the linking members or the pivot point of the compartment door slides within the slot and thereby causes the pivot point of the compartment door to move when the door is rotated. However, these prior art hinge assemblies are unsatisfactory for use with an airplane compartment door because they fail to maintain quality required in airplane structures when subjected to stress. To meet airplane standards of quality, the slot of the prior art hinge assemblies must be made of substantially friction-free material and must be manufactured to close tolerances. The pins or rollers that attach to the linking members or to the pivot point of the compartment door and that slide in the slots of the prior art hinge assemblies must be able to move in substantially friction-free relationship along the longitudinal direction of the slot, and must also be restricted from movement in any other direction. It is difficult to maintain acceptable tolerances in the slot for any substantial period of time due to normal wear between the slots and their respective pins or rollers. As the slots wear out, the compartment door becomes more susceptible to wobbling and rattling when opened and thus fails to meet the requisite quality standards.
Another prior art hinge assembly that moves the pivot axis of the compartment door when the compartment door is rotated is known as a Sepa hinge. The Sepa hinge consists of a plurality of pivotally connected linking members and support members and resembles a standard door hinge. The Sepa hinge is very bulky and heavy. If installed in an airplane overhead compartment, the Sepa hinge would occupy a considerable amount of space within the compartment. Moreover, the bulk and weight of the Sepa hinge make it difficult to combine the Sepa hinge with a mechanism for exerting a force on the compartment door to automatically open and hold the door when the compartment door is unlatched. Also, the attachment points of the linking members to the support members and to other linking members in the Sepa hinge are nonreleasable and therefore prevent removal of the compartment door. Without being able to remove or lower the compartment door from its pivot axis, it is not possible to gain access to and remove the ceiling panels of the airplane. Maintenance and repair of airplanes requires that the ceiling panels be removable.
Therefore, it is an object of this invention to provide a new and improved hinge assembly that will smoothly and efficiently open compartment doors and that is resistant to wear when subjected to stress.
It is a further object of this invention to provide a new and improved compartment door hinge assembly that has a movable pivot axis and that cooperates with a mechanism capable of exerting a force on a compartment door to automatically open and hold open an unlatched compartment door.
It is yet another object of this invention to provide a new and improved compartment door apparatus, including a door hinge assembly cooperating with an energy storage device, that is lightweight and small so that the entire apparatus may be mounted within a compartment without occupying much internal space.
It is yet another object of this invention to provide a new and improved compartment door hinge assembly cooperating with an energy storage device that can be partially disconnected to allow the compartment door to be lowered, providing quick and easy access to the ceiling panels in an airplane, and that can be quickly and easily reconnected.